EuroPCR Session Examines Evidence for Bioresorbable Scaffolds

May 22, 2014—At the EuroPCR 2014 congress in Paris, France, a session was devoted to the development of evidence for bioresorbable vascular scaffolds, which represent a new era of vascular restoration in interventional cardiology. 

As summarized in the EuroPCR announcement, a panel of experts analyzed the available data and concluded that bioresorbable, fixed-strut vascular scaffolds are associated with increased acute thrombogenicity due to flow disturbances. Therefore, patients implanted with these devices need to receive ongoing dual-antiplatelet therapy. The panelists also noted that endothelialization is further delayed when these devices are used compared with when thin-strut drug-eluting stents are used.

In the the EuroPCR press release, Tan Huay Cheem, MD, of National University Heart Centre in Singapore, commented, “I think one of the greatest attractions of bioresorbable vascular scaffolds is the idea that normal vasofunction will eventually be restored. There is some evidence from imaging data to show that the plaque is modified alongside the stent dissolving. There is also positive remodeling taking place, and this vascular response is one of the most exciting aspects of the technology.”

The diversity of devices that are approaching the market was also emphasized. Michael Joner, MD, who is CEO of CVPath Institute in Gaithersburg, Maryland, stated, “There is no uniformity in these devices and no class effect. Every device needs to be assessed carefully and individually. The inflammatory response associated with these devices depends on the pace of degradation, so we need to assess how they degrade over time, and this has important implications for patient safety.”

Dr. Joner added, “The long-term safety of bioresorbable vascular scaffolds will depend on various things: if we can see that arterial healing occurs over time, if full degradation occurs in the absence of excess inflammation, and if we do not see too much positive remodeling, then these devices can be very beneficial to patient care.”

Professor Chaim Lotan, MD, stated, “I think the technology is very interesting, but the bar that has been set by drug-eluting stents is very high and bioresorbable vascular scaffolds will need to match this, especially with regard to strut thickness and deliverability.” Prof. Lotan is Head of the Cardiovascular Institute at Hadassah University Hospital in Jerusalem, Israel. 

Prof. Lotan also observed that there is a lack of long-term safety data. He said, “We need follow-up data of more than 5 years duration, possibly up to 10 years, because our previous experience with bare-metal stents and drug-eluting stents has shown that we still see changes up to 7 years. So we await long-term data for bioresorbable vascular scaffolds with regard to device behavior and degradation patterns. We have seen cases where the stent has not yet degraded after 3 years, and this could pose a problem for patients. Will the degradation occur as planned? Will the struts be apposed? Will we see late events such as thrombosis? All these are unanswered questions.”

Finally, Robert-Jan van Geuns, MD, of the University of Rotterdam in the Netherlands, pointed to the potential advantages of using bioresorbable vascular scaffolds. Dr. van Geuns stated, “In general, the data emerging are in line with the theory behind these devices: that vascular restoration therapy is going to heal vessels better than metallic stents. The long-term data has been demonstrated in noncomplex patients, and we see that these patients do very well. We still need more data in more complex patients; there are now some nonrandomized data available that are out to 6 months, but we have to wait for the evidence in more complex patients before we can advocate the use of these devices in such patients.”